Objective To compare the effects of flap delay and vascular endothelial growth factor (VEGF) on the viability of the rat dorsal flap. Methods Thirty rats were divided into 3 groups: saline group, flap delay group and VEGF group. The rats in flap delay group underwent flap delay by keeping bipedicle untouched, and the cranial pedicle was cut 7 days later. The rats in VEGF group were given VEGF solution locally when the flaps were elevated in the operation. The ratsin saline group were given saline solution in the same way. Five days after thesingle pedicle flaps were performed, the flap survival rate was measured. Theflap tissues were collected to measure and analyze the microvascular density, diameter and sectional area by immunochemical method. Results The flap survival rate of flap delay group was similar to that of VEGF group andthere is no statistically significant difference(Pgt;0.05). The vascular diameter of flap delay group was much larger than that of saline group and VEGF group, showing statistically significant difference (Plt;0.05). The vascular density of VEGF group was much higher than that of saline group and flap delay group, showing statistically significant difference (Plt;0.05). The vascular sectional area of flap delay group was similar to that of VEGF group(Pgt;0.05). Conclusion The change in the flap after flap delayis manifested as obvious dilatation of microvessels, while the change in the flap after the injection of VEGF is manifested as obvious vascular proliferation. Both flap delay and VEGF can increase the vascular sectional area and the viability of the flap, but the mechanism is different.
Objective To verify the effect of palatoplasty with or without velopharyngeal muscular reconstruction on the velar movement through the lateral radiography. Methods From October 1988 to October 2000, 62 patients with cleft palate and velopharyngeal insufficiency were treated. Of them, 32 were repaired by velopharyngeal muscular reconstruction (group A) and 30 by modified von Langenbeck’s procedure (group B). The lateral radiographs and cephalometric analysis were taken. The velopharyngeal closure, velar extensibility, the angle changes of velar elevation, the distance changes of velar levator eminence based on anatomy (LEA) to velopharyngeal closure line (VCL), the varieties in LEA, the comparison of LEA and velar levator eminence based on phonation (LEP), the distance comparison between posterior nasal spine (PNS) to LEA and LEP through soft palate line (SPL) were measured. Results During the phonation, group A was significantly greater than group B in the velopharyngeal closure rate(Plt;0.01)， the velar extensibility(Plt;0.05) and the location comparison between LEA and LEP(Plt;0.01); group B was significantly greater than group A in velar elevation angle (Plt;0.05), the varieties in LEA(Plt;0.05). In velar rest position, the distance of LEA to VCL was greater inB group than in A group(Plt;0.01). There was significant difference in thedistance comparison between LEA and LEP(Plt;0.05), difference between LEA and LEP(Plt;0.01) and the distance PNS-SPL-LEA and PNSSPL-LEP(Plt;0.05) within group B; contrary to the results within group A(P＞0.05). Conclusion The velopharyngeal muscular reconstruction in palatoplasty can result in a near normalizationof anatomic measurement of velar levator muscles and improve the velar functionand velopharyngeal competence. Repositioning of velar muscles in a more anatomic correct, transverse position is more important to improve the velar length andaccordant velar movement with velopharyngeal muscles in functional palatoplasty. The velar angle change and velar elevation during phonation are not determinative factors for velopharyngeal competence.